Oil collecting device for an internal combustion engine

ABSTRACT

The invention relates to an oil collecting arrangement for an internal-combustion engine having an oil collecting housing ( 2 ) arranged below a crankcase, which oil collecting housing ( 2 ) has at least two sections of different space depths, in a deeper space section ( 4 ), an oil scavenging line ( 8 ) being provided by means of which the lubricating oil is delivered to the consuming devices by way of a pump. It is suggested that, in the oil collecting housing ( 2 ), a separate insertion part ( 18 ) is fastened which, on the one hand, has an oil barrier ( 22, 28 ) aligned transversely to the longitudinal dimension of the oil collecting housing ( 4 ) ( 2 )?, which oil barrier ( 22, 28 ) prevents a flowing back of the lubricating oil from the deeper space section ( 4 ) into the crank space and/or into the flatter space section ( 12 ) in the inclined position of the internal-combustion engine, and which, on the other hand, has oil return ducts ( 34, 38, 40 ) for the lubricating oil flowing back from the cylinder head.

[0001] The invention relates to an oil collecting arrangement for aninternal-combustion engine according to the characteristics of thepreamble of claim 1.

[0002] From U.S. Pat. No. 5,103,782, an oil collecting arrangement ofthe above-mentioned type is known in the case of which the oil pan orthe oil collecting housing of the internal-combustion engine has twospace sections which have different depths along the longitudinaldimension of the crankcase. In the deeper space section constructed asan oil pan, an oil scavenging device is provided by means of which theoil is returned to the consuming devices. For the targeted return of theoil situated in the flatter space, corresponding oil conducting ribs areprovided. During uphill drives, particularly in the case of a motorvehicle having cross-country mobility, there is the risk that thelubricating oil situated in the deeper space will return into thecrankcase by way of the flatter space section. In addition to splashinglosses, there is the danger that, in the area of the oil scavengingdevice, insufficient oil will be available for the oil supply to theconsuming devices, or that air is taken in instead of oil.

[0003] In addition, it is known (see Special Printing from MTZMotortechnische Zeitschrift 52, 1991, Page 9, 10) to return lubricatingoil from the cylinder head by way of oil return ducts integrated in anoil pan top part into the oil sump, which oil return ducts extend tobelow the oil level.

[0004] It is an object of the invention to design an oil collectingarrangement for an internal-combustion engine such that, on the onehand, a reliable and fast oil return is ensured from the consumingdevices to the oil sump and that, on the other hand, it is ensured that,also in the case of an inclined position of the internal-combustionengine, a return flow of the lubricating oil from the deeper spacesection into the crank space and/or into the flatter space section isprevented. With respect to the manufacturing these two functions are tobe integrated in a simple manner and therefore also at reasonable costin the oil collecting arrangement.

[0005] The object is achieved by means of the characteristics indicatedin claim 1. The insertion part constructed separately from the oilcollecting arrangement is, on the one hand, constructed with an oilbarrier required between the two space sections and, furthermore, hasoil return ducts by way of which the oil flowing back from the cylinderhead directly arrives under the oil level of the lubricating oilsituated in the deeper space section. As a result, the oil collectinghousing can be manufactured in a simple manner with respect to castingbecause the two above-described functions are implemented in theinsertion part constructed separately with respect to the oil collectinghousing.

[0006] Additional advantageous embodiments and improvements of the oilcollecting arrangement according to the invention are contained in thesubclaims. The insertion part consists of a center part having an oilholding edge and an oil shut-off wall and two side parts in which oilreturn ducts from the cylinder head are integrated.

[0007] The insertion part is advantageously made of plastic and, as awhole, therefore contributes to a weight reduction of theinternal-combustion engine. Furthermore, such a plastic insertion partcan be produced in a simple manner, for example, by means of injectionmolding.

[0008] An embodiment of the invention is explained in detail in thefollowing description and drawing.

[0009]FIG. 1 is a first perspective view of an oil collectingarrangement;

[0010]FIG. 2 is a second perspective view of an oil collectingarrangement;

[0011]FIG. 3 is a top view of the oil collecting arrangement;

[0012]FIG. 4 is a sectional view along Line IV-IV in FIG. 3;

[0013]FIG. 5 is a sectional view along Line V-V in FIG. 3;

[0014]FIG. 6 is a sectional view along Line VI-VI in FIG. 3;

[0015]FIG. 7 is a sectional view along Line VII-VII in FIG. 3; and

[0016]FIG. 8 is a view of a two-stage oil pump inserted in the oilcollecting arrangement.

DESCRIPTION OF THE EMBODIMENT

[0017] An oil collecting housing 2 has a space 4, in the followingcalled a first oil collecting space, in which the oil collects which isnecessary for the lubricating oil supply of the internal-combustionengine. In the first oil collecting space 4, an oil snorkel 6 is placedat its lowest point, which oil snorkel 6 leads by way of a first oilscavenging line 8 to the suction side of an oil pump 10. In the oilcollecting housing 2, a second space 12 is arranged, which, in thefollowing, is called a second oil collecting space and which has aflatter construction than the first oil collecting space 4. In thesecond oil collecting space 12, an oil snorkel 14 is also arranged atits lowest point which is connected by way of a second oil scavengingline 16 with a second suction side of the oil pump 10 constructed as adouble pump 10.

[0018] A plastic insertion piece 18 is inserted in the oil collectinghousing 2, the construction of which insertion piece 18 will bedescribed in detail in the following. The insertion piece 18 has acenter part 20 which, as illustrated particularly in FIGS. 2 and 3, inthe installed condition, separates the two oil collecting spaces 4, 12from one another. In this case, the center part 20 has a first side wall22 aligned toward the first oil collecting space 4, which side wall 22is provided with a wall section 23 forming a shut-off wall for thelubricating oil. A second side wall 24 separating the two oil collectingspaces 4, 12 engages in a holding groove 48 arranged on the bottom ofthe oil collecting space 12 and extending transversely to thelongitudinal dimension of the oil collecting housing 2. Thistongue-and-groove connection is additionally sealed off by silicone orflexible foam, because it is to be avoided that, in an inclined positionof the motor vehicle, lubricating oil reaches the second oil collectingspace 12 from the first oil collecting space 4. In contrast, the firstside wall 22 of the insertion part 18 is constructed such that,particularly in an inclined position of the engine, the lubricating oilcan flow from the first oil collecting space 4 under the center part 20.As a result, this space section is also utilized for receiving the oilvolume required for a reliable lubricating oil supply.

[0019] A covering wall 26 of the center part 20 is lowered toward thecenter (see intersection Line IV-IV in FIG. 3) of the oil collectinghousing 2 and consists of two lowered partial surfaces 26 a and 26 bwhich change in the center into a straight partial surface 26 c. Theside edge 28 of the covering wall 26 aligned toward the first oilcollecting space 4, in the following called oil holding edge, is used asan oil barrier which, when the vehicle drives in hilly terrain, preventsthat the lubricating oil flows from the first oil collecting space 4into the second oil collecting space 12. As illustrated in FIG. 8, thesecond oil scavenging line 16 extending to the second oil collectingspace 12 extends above the centrally aligned straight partial surface 26c.

[0020] Two side parts 30 and 32 are molded to the center part 20, inwhich side parts 30 and 32 some of the oil return ducts leading from thecylinder head to the first oil collecting space 4 are integrated. Forthis purpose, the two side parts 30 and 32 have oil return flow openings34 which are surrounded by sealing rings 36. The side part 32 providedwith five oil return flow openings 34 in the embodiment extends alongthe entire length of the oil collecting housing 2, while the side part30 provided in the embodiment with four oil return flow openings 34extends from the second oil collecting space 12 to the start of thefirst oil collecting space 4. The oil return flow openings 34 arrangedin the two side parts 30 and 32 lead into one oil collecting duct 38 and40 respectively which are provided at their lower ends with one oildischarge opening 42 and 44 respectively. The two oil collecting ducts38 and 40 are closed off, with the exception of the oil return flowopenings 34 leading to the crankcase (not shown), by means of coveringelements 46 which are fastened, for example, by vibration welding, tothe side parts 30, 32. When the oil collecting housing 2 is screwed to acrankcase bottom part, which is not shown, the bores made on the flangesurface of the crankcase bottom part corresponding to the oil returnflow openings 34 are sealingly fitted by means of their bore edges onthe sealing rings 36. By means of the oil return flow ducts integratedin the crankcase and the oil collecting ducts 38 and 40 extending belowthe oil level of the lubricating oil situated in the first oilcollecting space 4, it is ensured that the lubricating oil, despite thepressure pulsations caused by crankshaft and piston movements, israpidly returned from the consuming devices back into the first oilcollecting space 4. The second oil collecting space 12 collects thelubricating oil from the main bearings and the lubricating oil from theinjection nozzles, which are not shown, for the piston cooling, whichlubricating oils are pumped by way of the second oil scavenging line 16back into the first oil collecting space 14 (4?).

[0021] The plastic insertion part 18 fixed by means of the engagement ofthe side wall 24 in the holding groove 48 is screwed on in a captivemanner by means of fastening lugs 50 molded to the center part 20 and tothe two side parts 30 and 32 in the oil collecting housing 2. On bothlongitudinal sides of the oil collecting housing 2, a sealing surface 52is provided by way of which the insertion part 18 is sealed off withrespect to the oil guiding housing 2 with its two side parts 30 and 32.

[0022] Particularly because of the oil holding edge 28 constructed as anoil barrier and because of the oil shut-off wall 23, the insertion part18 is designed such that, also during uphill driving of the vehicle ofup to 45°, it is prevented that the lubricating oil can flow from thefirst oil collecting space 4 into the crank space and/or into the secondoil collecting space 12. By means of the oil scavenging line 16 arrangedin the second oil collecting space 12, it is ensured that, independentlyof the inclined position of the vehicle, the lubricating oil from thesecond oil collecting space 12 by way of the oil scavenging line 16 andby way of an air separator 54 reaches the first oil collecting space 4,from where it is returned to the consuming devices by means of the firstpumping stage. Because both pumping stages operate constantly, it isensured by the air separator 54 that the air taken in particularlyduring downhill driving or when the motor vehicle is braked from thesecond oil collecting space 12 is separated and therefore does not reachthe crankcase or the consuming devices.

1. Oil collecting arrangement for an internal-combustion engine havingan oil collecting housing arranged below a crankcase, which oilcollecting housing has at least two sections of different space depths,in a deeper space section, an oil scavenging line being provided bymeans of which the lubricating oil is delivered to the consuming devicesby way of a pump, characterized in that, in the oil collecting housing(2), a separate insertion part (18) is fastened which, on the one hand,has an oil barrier (22, 28) aligned essentially transversely to thelongitudinal dimension of the oil collecting housing (2), which oilbarrier (22, 28) prevents a flowing back of the lubricating oil from thedeeper space section (4) into the crank space and/or into the flatterspace section (12) in the inclined position of the internal-combustionengine, and which, on the other hand, has oil return ducts (34, 38, 40)for the oil flowing back from the cylinder head.
 2. Oil collectingarrangement according to claim 1, characterized in that the insertionpart (18) consists of a center part (20) separating the two spacesections (4, 12) and having an oil holding edge (28), and of two sideparts (30, 32) accommodating the oil return ducts (34, 38, 40).
 3. Oilcollecting arrangement according to claim 2, characterized in that thetwo side parts (30, 32) have oil return flow openings (34) which eachlead into a collecting duct (38, 40) which extends into the deeper spacesection (12).
 4. Oil collecting arrangement according to one of thepreceding claims, characterized in that the insertion part 18) consistsof plastic and is screwed into the oil collecting housing (2).
 5. Oilcollecting arrangement according to one of claims 2 to 4, characterizedin that a holding groove (48) is provided in the flatter space section(4), a side wall (24) of the center part (20) engaging in the holdinggroove (48).